查看内核
# uname -s -r Linux 2.6.32-358.el6.x86_64
查看发布版本
# cat /etc/redhat-release CentOS release 6.4 (Final)
查看CPU架构
# arch x86_64(x86_64表示64位机器/i686表示32位机器) # getconf LONG_BIT 64
（2）用户设置
添加用户
# /usr/sbin/useradd user1 -d /home/user1 -G nobody # passwd user1 New password: 123456 Retype new password: 123456 passwd: all authentication tokens updated successfully.
确认用户
# id user1
删除用户
# userdel -r user1
赋予root权限
# usermod -G wheel hoge # vi /etc/pam.d/su auth required pam_wheel.so use_uid # <= 取消注释
用户一览
# cat /etc/passwd
（3）网络设置
设置IP
# vi /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE="eth0"
OTPROTO="static" # <=
HWADDR="00:0C:29:53:A5:AE"
IPV6INIT="no" # <=
NM_CONTROLLED="yes"
ONBOOT="yes"
TYPE="Ethernet"
UUID="1ca6acf4-ebce-415a-a89b-bf89a67819ff"
IPADDR="xxx.xxx.xx.xx" # <=
NETMASK="255.255.255.0" # <=
GATEWAY="xxx.xxx.xx.xx" # <=
DNS1="xxx.xxx.xx.xx" # <=
# service network restart
Shutting down interface eth0:
......
Connection activated [ OK ]
# ifconfig
eth0 Link encap:Ethernet HWaddr 00:0C:29:2F:D5:58
inet addr:xxx.xxx.xx.xx Bcast:xxx.xxx.xx.xx Mask:255.255.255.0
......
卸载NestworkManager服务
# chkconfig NetworkManager off # yum -y remove NetworkManager
关闭IPv6
# service ip6tables stop # chkconfig ip6tables off # echo "install ipv6 /bin/true" >> /etc/modprobe.d/disable-ipv6.conf # vi /etc/sysconfig/network NETWORKING_IPV6=no IPV6INIT=no # vi /etc/sysconfig/network-scripts/ifcfg-eth0 # shutdown -r now # lsmod | grep ipv6 没有ipv6模块 # netstat -an | grep ffff 没有:ffff:开始的IP # ifconfig 没有inet6 addr开始的文字
（4）包管理设置
yum清理
# yum clean all Loaded plugins: fastestmirror, security Cleaning repos: base extras updates Cleaning up Everything # yum makecache Loaded plugins: fastestmirror, security Determining fastest mirrors …………. Metadata Cache Created
yum更新
# yum -y update
自动更新
# yum -y install yum-cron # vi /etc/sysconfig/yum-cron CHECK_ONLY=yes DOWNLOAD_ONLY=yes # /etc/rc.d/init.d/yum-cron start # chkconfig yum-cron on # chkconfig --list yum-cron
自动查找最快镜像
# yum -y install yum-plugin-fastestmirror # vi /etc/yum/pluginconf.d/fastestmirror.conf enabled=0 ←0：无效 1：有效
添加repository
# vi /etc/yum.repos.d/CentOS-Base.repo # rpm -Uvh http://pkgs.repoforge.org/rpmforge-release/rpmforge-release-0.5.3-1.el6.rf.x86_64.rpm # vi /etc/yum.repos.d/rpmforge.repo enabled=0 # yum --enablerepo=rpmforge install xxxx # rpm -Uvh http://ftp.riken.jp/Linux/fedora/epel/6/x86_64/epel-release-6-8.noarch.rpm # vi /etc/yum.repos.d/epel.repo enabled=0 # yum --enablerepo=epel install xxxx
（5）设置vim
# yum -y install vim-enhanced # vi /etc/profile alias vi='vim' # source /etc/profile # vi /etc/vimrc
（6）安全设置
关闭SELinux
# getenforce # setenforce 0 ←临时关闭 # vi /etc/sysconfig/selinux SELINUX=enforcing ↓ SELINUX=disabled
停止iptables
# /etc/rc.d/init.d/iptables stop iptables: Flushing firewall rules: [ OK ] iptables: Setting chains to policy ACCEPT: filter [ OK ] iptables: Unloading modules: [ OK ] # chkconfig iptables off # chkconfig --list iptables iptables 0:off 1:off 2:off 3:off 4:off 5:off 6:off
（7）系统运行情况
磁盘使用情况
# df -h # yum -y install sysstat # iostat
内存使用情况
# free -m
CPU和内存
# cat /proc/cpuinfo # cat /proc/meminfo
（8）其他
修改hostname
# hostname localhost.localdomain # vi /etc/sysconfig/network NETWORKING=yes #HOSTNAME=localhost.localdomain HOSTNAME=MyNewHostName NETWORKING_IPV6=no # vi /etc/hosts 127.0.0.1 MyNewHostName 127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4 ::1 localhost localhost.localdomain localhost6 localhost6.localdomain6 #hosts文件每行格式：IP地址 hostname aliases #保留localhost的定义，因为Apache、Postfix、sendmail等服务会用到 # shutdown -r now # uname -a Linux MyNewHostName 2.6.32-358.el6.x86_64 ...... 临时修改 # hostname MyTmpHostName # /etc/init.d/network restart
本地语言化
# yum -y groupinstall "Japanese Support" # vi /etc/sysconfig/i18n LANG="en_US.UTF-8" ↓ LANG="ja_JP.UTF-8" # source /etc/sysconfig/i18n # echo $LANG ja_JP.UTF-8 # shutdown -r now
停止不必要的服务
# chkconfig --list | grep 3:on # service ip6tables stop # chkconfig ip6tables off
编码转换nkf(Network Kanji Filter)
# yum -y install nkf # vi readme.txt test 漢字 # nkf -g readme.txt UTF-8 (LF) # nkf -s --overwrite readme.txt # nkf -g readme.txt Shift_JIS (LF) # nkf -j --overwrite readme.txt # nkf -g readme.txt ISO-2022-JP (LF)
安装gcc
# rpm -qa gcc # yum -y install gcc gcc-c++ # gcc -v Using built-in specs. Target: i686-redhat-linux ………… gcc version 4.4.7 20120313 (Red Hat 4.4.7-4) (GCC)
安装PCRE
# cd /usr/local/src # wget ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/pcre-8.35.tar.gz # tar zxvf pcre-8.35.tar.gz # cd /usr/local/src/pcre-8.35 # ./configure --prefix=/usr/local/pcre/8.35 # make clean # make && make install # PATH=/usr/local/pcre/8.35/bin:$PATH # vi /etc/ld.so.conf /usr/local/pcre/8.35/lib ←末尾追加 # ldconfig # rpm -qa pcre pcre-7.8-6.el6.x86_64 # pcretest -C PCRE version 7.8 2008-09-05
安装OpenSSL
# cd /usr/local/src # wget http://www.openssl.org/source/openssl-1.0.1h.tar.gz # tar xzvf openssl-1.0.1h.tar.gz # cd openssl-1.0.1h # ./config shared -fPIC # make && make install # vi /etc/ld.so.conf /usr/local/ssl/lib ←末尾追加 # ldconfig # ldconfig -f /etc/ld.so.conf -vp|grep ssl/lib libssl.so.1.0.0 (libc6) => /usr/local/ssl/lib/libssl.so.1.0.0 libssl.so (libc6) => /usr/local/ssl/lib/libssl.so libcrypto.so.1.0.0 (libc6) => /usr/local/ssl/lib/libcrypto.so.1.0.0 libcrypto.so (libc6) => /usr/local/ssl/lib/libcrypto.so # /usr/local/ssl/bin/openssl version OpenSSL 1.0.1h 5 Jun 2014
NTP同步时间
引用
# yum -y install ntp
# mv /etc/ntp.conf /etc/ntp.conf.org
# vi /etc/ntp.conf
driftfile /var/lib/ntp/drift
server 0.jp.pool.ntp.org
server 1.jp.pool.ntp.org
server 2.jp.pool.ntp.org
server 3.jp.pool.ntp.org
# ntpdate 0.jp.pool.ntp.org
# /etc/init.d/ntpd start
# ntpq -p
# ntpstat
# mv /etc/ntp.conf /etc/ntp.conf.org
# vi /etc/ntp.conf
driftfile /var/lib/ntp/drift
server 0.jp.pool.ntp.org
server 1.jp.pool.ntp.org
server 2.jp.pool.ntp.org
server 3.jp.pool.ntp.org
# ntpdate 0.jp.pool.ntp.org
# /etc/init.d/ntpd start
# ntpq -p
# ntpstat
引用
CentOS默认安装NTP服务、NTP服务采用的是Server/Client的模式、一台机器同时是ntp服务器和ntp客户端。
同步方法：ntpdate、ntpd
ntpdate：强制修改系统时间（需要定期同步修正cpu tick）
[root@linux ~]# ntpdate time.ntp.org
[root@linux ~]# crontab -e
0 12 * * * * /usr/sbin/ntpdate time.ntp.org
每天12点强制同步一下时间
ntpd服务：修正系统时间并修正cpu tick
[root@linux ~]# vi /etc/ntp.conf
#restrict 127.0.0.1
restrict 192.168.21.0 mask 255.255.255.0 nomodify notrap
server -4 192.168.21.1 *** -4代表通过IPv4连接服务器
[root@linux ~]# /etc/init.d/ntpd start
[root@linux ~] # netstat -ln|grep 123
[root@linux ~] # ntpstat
每64秒与上源服务器同步一次,随着误差减小,逐步增加同步的间隔
需要确保是否有权限连接到服务器端。
先使用ntpdate强制同步时间，之后使用ntpd服务同步时间
安装
# yum -y install ntp
# ntpd --version
设置
# cp /etc/ntp.conf /etc/ntp.conf.org
# vi /etc/ntp.conf
手动同步
# ntpdate pool.ntp.org
启动ntpd
# service ntpd start
# chkconfig ntpd on
确认
# ntpq -p
# ntpstat
# ntpd -gq 强制更新
同步方法：ntpdate、ntpd
ntpdate：强制修改系统时间（需要定期同步修正cpu tick）
[root@linux ~]# ntpdate time.ntp.org
[root@linux ~]# crontab -e
0 12 * * * * /usr/sbin/ntpdate time.ntp.org
每天12点强制同步一下时间
ntpd服务：修正系统时间并修正cpu tick
[root@linux ~]# vi /etc/ntp.conf
#restrict 127.0.0.1
restrict 192.168.21.0 mask 255.255.255.0 nomodify notrap
server -4 192.168.21.1 *** -4代表通过IPv4连接服务器
[root@linux ~]# /etc/init.d/ntpd start
[root@linux ~] # netstat -ln|grep 123
[root@linux ~] # ntpstat
每64秒与上源服务器同步一次,随着误差减小,逐步增加同步的间隔
需要确保是否有权限连接到服务器端。
先使用ntpdate强制同步时间，之后使用ntpd服务同步时间
安装
# yum -y install ntp
# ntpd --version
设置
# cp /etc/ntp.conf /etc/ntp.conf.org
# vi /etc/ntp.conf
手动同步
# ntpdate pool.ntp.org
启动ntpd
# service ntpd start
# chkconfig ntpd on
确认
# ntpq -p
# ntpstat
# ntpd -gq 强制更新
GHOST: glibc vulnerability (CVE-2015-0235)
# yum update glibc # rpm -qa | grep glibc 2.12-1.149.el6_6.5